Tomcat Ubuntu Security

[spangeman]

I have installed tomcat on my Ubuntu Home 11.10 system and can successfully access the test page online after port forwarding on 8080 within my router.

I have not made any other changes to the router, Ubuntu or the tomcat install, everything else has remained standard. I intend on using this to play around with Java Servlets and basic web development for my own personal use.

What steps, if any, would you suggest I take to ensure this is secure? Should I change anything within the Tomcat configuration?
This seemed like a good idea to limit access -

http://www.seankilleen.com/2010/09/how-to-allow-only-specific-ip-addresses_30.html

But I am open to any other recommendations.

Thanks